1. Technical Field
The exemplary embodiments are directed towards an electrical connection box and a method of assembling the electrical connection box. Specifically, in an electrical connection box for a motor vehicle which houses an internal circuit body within an upper case and a lower case, the exemplary embodiments improve assembly operability of the internal circuit body, and accurately position and assemble the electrical connection box without generating flexure.
2. Background Technology
In this type of electrical connection box, in which an internal circuit body is inserted into one of the cases and then the other case is assembled onto the first case, when the internal circuit body is inserted into and engaged with the case, it needs to be accurately positioned and fixed. It is also necessary to increase assembly operability.
Because of this, various proposals have been made. There are many instances in which a round hole for positioning, and an elongate hole for adjusting position and preventing rotation are arranged.
For example, in Japanese Published Utility Model Patent Application 6-38291 (JP-U-6-38291), as shown in FIGS. 13(A) and (B), in a box in which a printed circuit board 101 is housed in a housing 100, and a cover 102 is attached, at least two positioning pins 103a, 103b are protrudingly arranged on the cover 102. A positioning hole 104 and an elongate hole 105 into which the positioning pins 103 are inserted are arranged in the printed circuit board 101, and a positioning boss 106 and a rotation-preventing boss 107 are arranged on the housing 100.
The elongate hole 105 arranged in the printed circuit board 101, which is arranged in the cover, is arranged substantially at the center, and the positioning hole 104 is arranged at a peripheral position of the printed circuit board 101. Meanwhile, on the housing 100 side, a cylindrical positioning boss 106 is arranged at a position corresponding to the elongate hole 105 in the printed circuit board, and an oblong rotation-preventing boss 107 is arranged at a position corresponding to the positioning hole 104 in the printed circuit board. With respect to the positioning boss 106 arranged at the center of the housing 100, the rotation-preventing boss 107 arranged at the peripheral side is arranged on the line parallel to a surrounding wall 100a on a long side of the housing 100 and is positioned substantially at the center of a surrounding wall 100b on a short side.
That is, the positioning pin 103a at the center of the cover 102 goes through the elongate hole 105 of the printed circuit board and is inserted into the round positioning boss 106 of the housing 100. The positioning pin 103b at the periphery of the cover 102 is inserted into the oblong rotation-preventing boss 107 of the housing via the positioning hole 104.
In the box, the positioning pins 103a, 103b of the cover 102 pass through the positioning hole 104 and the elongate hole 105 of the printed circuit board 101, and the printed circuit board is fixed with screws 120. Thus, the printed circuit board 101 fixed with the cover 102 in advance is inserted into the housing 100, and the positioning pin 103a protruded from the center is inserted into the positioning boss of the housing 100, and the positioning pin 103b protruded from the periphery is inserted into the rotation-preventing boss 107 of the housing 100.
That is, in JP-U-6-38291, the positioning pin 103a at the center of the cover 102 goes through the elongate hole of the printed circuit board and then is engagingly positioned in a cylindrical boss on the housing side. Meanwhile, the positioning pin 103b at the periphery passes through the round positioning hole of the printed circuit board and is positioned, and then is engaged with the oblong rotation-preventing boss on the housing side.
However, if there is distortion or flexure in the cover 102, the positioning pins 103 are inclined. Additionally, if there is distortion or flexure in the housing 100, the bosses 106 and 107 are inclined.
Thus, if there is distortion or flexure in the cover 102, it is difficult to insert the positioning pin 103a into the elongate hole 105 of the printed circuit board 101. In the same manner if there is distortion or flexure in the housing 100, there is a problem that it is difficult to insert the positioning pin 103b into the oblong rotation-preventing boss 107 of the housing 100.